Methods and apparatus for recording data on and deleting already recorded data from a recording medium

ABSTRACT

In a recording method for a recording medium having a data recording area on which a data recording and/or reproducing operation is carried out, and a management data area on which management data to manage a recording and/or reproducing operation for the recording medium are recorded, when new data are recorded on the recording medium in a state where data have been already recorded on the recording medium and a data-recordable area on which the new data can be recorded exists on the data recording area, the recording operation of the new data is started from the head position of the data-recordable area on the basis of the management data recorded on the management data area, and data which have been already recorded on the recording medium are deleted by the same data amount as the new data to be recorded on the data-recordable area from a position on the data recording area of the recording medium at which the recording operation is instructed to start.

This is a continuation of application Ser. No. 08/422,121 filed on Apr.13, 1995 abandoned.

BACKGROUND

1. Field of the Invention

The present invention relates to a recording method and a recordingapparatus for a recording medium. More particularly, the presentinvention relates to a recording method and a recording apparatus for arecording medium having management data to manage a data recordingand/or reproducing operation.

2. Background of the Invention

A disc-shaped data rewritable recording medium on which an user canfreely record music data or the like has been hitherto known. This typeof disc-shaped recording medium (hereinafter referred to as "disc") isprovided with a data area on which music data of pieces of music havebeen already recorded, and a data area (user's Table Of Contents,hereinafter referred to as "U-TOC") on which management data to manageunrecorded areas having no data recorded therein are recorded. The discis designed so that the management data are also rewritten in accordancewith various operations such as a recording operation, an editingoperation, a deleting operation, etc., for example.

For example, when a piece of music is recorded, a recording devicesearches a non-recording area on the disc on the basis of the managementdata in the U-TOC to record audio data in the searched non-recordingarea. On the other hand, a reproducing device searches from the U-TOC anarea on which a piece of music (track) to be reproduced is recorded, andaccesses the area to perform a reproducing operation.

A data recordable disc such as a magneto-optical disc has an advantagethat a random access can be more easily performed as compared with atape-shaped recording medium such as a DAT (digital audio tape), acompact cassette tape or the like. Accordingly, it is unnecessary torecord music data (plural pieces of music) from the inner peripheralside to the outer peripheral side on the disc so that the respectivemusic data are orderly arranged from a first track until an n-th trackin this order. That is, even when the respective pieces of music arephysically randomly recorded on the disc, the pieces of music can beorderly reproduced insofar as addresses from the first track to the n-thtrack at which the respective pieces of music are recorded are managedby the U-TOC as described above or the like. In the followingdescription, one piece of music is assumed to be recorded on one track,however, one piece of music may be recorded over plural tracks or on apart of one track.

Furthermore, each piece of music (track) is not necessarily recorded asa lump on a continuous part (hereinafter, the term of "part" means apart on which physically-continuous data are recorded), and it may bediscretely recorded on plural parts while divided into plural sub piecesof music (sub music data).

Particularly in a system for temporarily storing data read out from amagneto-optical disc into a buffer memory at a high transfer rate, thenreading out the data from the buffer memory at a low transfer rate toobtain audio reproduction signals, and then conducting a decodingprocessing on the audio reproduction signals, the reproduction audiosignals can be output without interruption even when the data read-outoperation from the magneto-optical disc is temporarily intercepted dueto access shift between parts.

Accordingly, by repeating a recording and reproducing operation and ahigh-speed access operation (an access operation which is finishedwithin a reproducible time in accordance with a data accumulation amountwhich is dependent on the difference between a data writing rate intothe buffer memory and a data reading rate from the buffer memory, therecording/reproducing operation of the pieces of music can be performedwith no trouble even when the music datum of a piece of music isphysically divided into plural sub music data and discretely recorded onthe disc.

For example, a data recording format as shown in FIG. 1 may be adopted.In this data recording format, each of first and second pieces of musicis physically continuously recorded on a part (for example, the firstand second pieces of music are recorded on a part M₁ and a part M₂respectively) while each of fourth and fifth pieces of music isdiscretely recorded on plural parts with being physically divided intoplural sub music data (for example, the fourth piece of music isdivisionally recorded on sub parts M₄(1) to M₄(4) and the fifth piece ofmusic is also divisionally recorded on sub parts M₅(1) to M₅(2). FIG. 1shows the recording format more schematically, and practically one partmay extend over several to several hundreds rounds (tracks) or more.

When the music data recording or deleting operation is repetitivelyperformed on the magneto-optical disc, empty areas occurs irregularly onthe disc due to the difference in music rendering time between pieces ofmusic to be recorded or between pieces of music to be deleted. However,with the data discrete recording operation as described above, forexample, a piece of music which is longer than a deleted piece of musiccan be partially or wholly recorded on a part on which the deleted pieceof music was recorded, so that the data recording area can beeffectively used (occurrence of vain data recording areas can besuppressed) by repeating the data recording/deleting operation. The datato be recorded on the disc are not limited to "pieces of music (musicaldata)", and any data may be recorded insofar as these data are audio(sound) signals. In the following description, it is assumed that apiece of music is recorded as an unit data (track) whose content iscontinuous.

Of course, it is required that the data recording operation on such adisc is continued while accessing plural parts serving as non-recordingareas, and the data reproducing operation from the disc is performedwhile accessing plural parts so that each piece of music is reproducedaccurately continuously. In order to satisfy this requirement, data forlinking parts for each piece of music, for example, the parts M₄(1) toM₄(4) shown in FIG. 1, and data indicating non-recording areas are heldas management data in the U-TOC which is rewritten every recordingoperation or deleting operation as described above. Accordingly, therecording and/or reproducing apparatus is controlled to read in themanagement data from the U-TOC to access the head of the data, whereby aproper recording/reproducing operation is performed.

FIG. 2 shows a data recording format on the disc. As shown in FIG. 2,the recording data on the disc are blocked (sectioned) on a clusterbasis. One cluster CL (=36 sectors) contains a sub data area of foursectors (1 sector=2352 bytes) and a main data area of 32 sectors, andone cluster is the minimum unit for recording. One cluster correspondsto a track of two to three rounds. An address is recorded every sector.

The sub data area of four sectors is used for sub data or as a linkingarea, and the management data, audio data, etc. are recorded on the maindata area of 32 sectors.

One sector is further divided into sound groups (not shown), and twosectors are divided into 11 sound groups. Data of 512 samples arerecorded in a sound group while shared to an L-channel and an R-channel.Each sound group has an audio data amount corresponding to a time of11.6 msec.

There have been utilized two recording methods when an user recordspieces of music, voices or the like using a disc system using a buffermemory as described above. In one recording method, a non-recording areaon which no data are recorded (hereinafter referred to as "free area")is automatically searched, and the recording operation is performed onthe searched free area. On the other hand, in the other recordingmethod, the deletion of past data is started from a portion on which arecording start operation is conducted, that is, a so-called overwriterecording operation is performed. In this specification, the term "pastdata" means data to be deleted or disused.

The data overwrite recording operation will be described below withreference to FIGS. 3A to 3D. In this case, it is assumed that fourpieces of music (music data M₁ to M₄) have been recorded on a disc asshown in FIG. 3A.

The data overwrite operation is performed, for example, in a case wherean user starts the recording operation in an overwritable mode at thetime when the reproduction of the first piece of music (first music dataM₁) is finished and the reproduction of the second piece of music(second music data M₂) is about to start, or in a case where the headposition of the second piece of music M₂ is accessed to temporarily stopthe reproducing operation of the second piece of music (second musicdata M₂) and the recording operation is started in an overwritable mode.These cases correspond to a case where an user wants to delete the musicdata of the second piece of music and record the music data of a newpiece of music, for example. That is, through this overwrite operation,a past piece of music on the disc is deleted in the same manner as thaton a compact cassette tape, and a new piece of music is recorded on thedeleted piece of music. In this specification, "past piece of music"means a piece of music to be deleted or disused.

Through this operation, in the disc system as described above, the headposition of the second piece of music (second music data M₂) and thesubsequent portion thereof are wholly deleted and set to a free area asshown in FIG. 3B. Thereafter, the recording operation of actual data ofa new second piece of music (new second music data M₂) is started fromthe head position of the free area as shown in FIG. 3C. When a recordingstop operation is performed at a time, the recording operation of thenew second piece of music (new second music data M₂) is completed.

However, the overwrite recording method as described above has a problemthat those data which are still needed by the user may beunintentionally deleted because the whole portion subsequent to therecording start point is deleted. For example, even when the user newlyrecords a piece of music whose rendition is finished within the totaltime of the pieces of music (music data M₂ and M₃) in FIGS. 3A to 3Dbecause he wants to leave the fourth piece of music, the piece of music(music data M₄) is deleted against his intention. If the user isfamiliar with the operation of the disc system, he would understand thatthe piece of music (music data M₄) is deleted. However, if the user isfamiliar with the recording operation for a compact cassette tape, butunfamiliar with the disc system, he would operate the disc system in thesame manner as the compact cassette tape, so that the above problem isliable to occur.

Furthermore, in a case where the user is familiar with the operation ofthe disc system and wants to delete the pieces of music (music data M₂and M₃) while leaving the piece of music (music data M₄) and overwrite anew piece of music on the deleted pieces of music (music data M₂ andM₃), the music data M₄ is temporarily altered to the music data M₂ byperforming a music order changing edition, and then the recording isstarted from the head position of the music data M₃. Therefore, theoverwrite recording operation itself becomes cumbersome.

Still furthermore, the actual recording operation is not started justwhen the recording operation is instructed because an editing operationof setting the recording start point and the subsequent portion theretoas a free area must be performed before the recording operation isstarted. Therefore, it takes some time to start the actual recordingoperation.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide arecording method of a recording medium which resolves theabove-mentioned problem.

It is another object of the present invention to provide a recordingapparatus of a recording medium which resolves the above-mentionedproblem.

According to the present invention, there is provided a recording methodfor a recording medium having a data recording area on which a datarecording and/or reproducing operation is carried out, and a managementdata area on which management data for managing a recording and/orreproducing operation for the recording medium are recorded. Therecording method is characterized in that when new data are required tobe recorded on the recording medium in a state where data have beenalready recorded on the recording medium and a data recordable (dataunrecorded) area exists on the data recording area, the recordingoperation of the new data is started from the head position of therecordable area on the basis of the management data recorded on themanagement data area, and those data which have been already recorded(hereinafter referred to as "already-recorded data") are deleted by thesame data amount as the new data to be recorded on the data recordablearea from a position on the data recording area of the recording mediumat which the recording operation of the new data is instructed to start.

According to the present invention, there is provided a recording methodfor a recording medium which has a data recording area on which a datarecording and/or reproducing operation is carried out, and a managementdata area on which management data for managing a recording and/orreproducing operation for the recording medium are recorded, and onwhich address data are recorded. Data are sectioned into plural blocksevery predetermined amount of data as a recording unit, and recorded onplural blocks of the data recording area. On the management data areaare recorded data indicating a read-out order of the plural blocks. Therecording method is characterized in that when new data are required tobe recorded on the recording medium in a state where data which aresectioned into plural blocks have been already recorded on the recordingmedium and a data recordable (data unrecorded) area exists on the datarecording area, the recording operation of the new data is started fromthe head position of the recordable area on the basis of the managementdata of the management data area, data which have been already recordedare deleted by the same data amount as the new data to be recorded onthe data recordable area from the position on the data recording area ofthe recording medium at which the recording operation of the new data isinstructed to start, and the data indicating the data read-out order onthe management data area are rewritten.

According to the present invention, there is provided a recordingapparatus for a recording medium which has a data recording area onwhich a data recording and/or reproducing operation is carried out, anda management data area on which management data for managing a recordingand/or reproducing operation for the recording medium are recorded, andon which address data are recorded. Data are sectioned into pluralblocks every predetermined amount of data as a recording unit, andrecorded on plural blocks of the data recording area. On the managementdata area are recorded data indicating a read-out order of the pluralblocks. The recording apparatus is characterized by including arecording unit, a memory, an encoder and a controller. The recordingunit serves to record data on the recording medium. The memory serves totemporarily store input data to be recorded on the recording medium. Theencoder serves to perform an encode processing to convert the data readout from the memory to recording data, and supply the recording data tothe recording unit. The controller serves to control the operation ofthe recording unit, the memory and the encoder. When new data arerecorded on the recording medium in a state where data have been alreadyrecorded on the recording medium and a data recordable (data unrecorded)area exists on the data recording area of the recording medium, thecontroller reads out the new data from the memory, and controls therecording unit to start its recording operation of the new data from thehead position of a data recordable area of the recording medium on thebasis of the management data recorded on the recording medium and todelete data which have been already recorded on the recording medium,from the position on the data recording area of the recording medium atwhich the recording operation of the new data is instructed to start bythe same data amount as the new data to be recorded from the headposition of the data recordable area of the recording medium.

According to the present invention, there is provided a recordingapparatus for a recording medium which has a data recording area onwhich a data recording and/or reproducing operation is carried out, anda management data area on which management data for managing a recordingand/or reproducing operation for the recording medium are recorded, andon which address data are recorded. Data are sectioned into pluralblocks every predetermined amount of data as a recording unit, andrecorded on plural blocks of the data recording area. On the managementdata area are recorded data indicating a read-out order of the pluralblocks. The recording apparatus is characterized by comprising arecording unit, a memory, an encoder and a controller. The recordingunit serves to record data on the recording medium. The memory serves totemporarily store input data to be recorded on the recording medium. Theencoder serves to perform an encode processing to convert the data readout from the memory to recording data, and supply the recording data tothe recording unit. The controller serves to control the operation ofthe recording unit, the memory and the encoder. When new data arerecorded on the recording medium in a state where data have been alreadyrecorded on the recording medium and a data recordable (data unrecorded)area exists on the data recording area of the recording medium, thecontroller controls the recording unit to delete data which have beenalready recorded on the recording medium, from the position on the datarecording area of the recording medium at which the recording operationof the new data is instructed to start and by data amount ofpredetermined recording units which are read out from the memory, and atthe same time the controller reads out the data from the memory everypredetermined recording units and controls the recording unit to startits recording operation of the new data from the head position of thedata recordable area.

According to the present invention, the past data are deleted from therecording medium by the same amount as the new data recorded on therecording medium, so that an user can grasp the data amount to bedeleted from the position on the recording medium at which the recordingis instructed to start, or a data deletion range.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a recording format on a disc;

FIG. 2 is a diagram showing a sector structure of data recorded on adisc;

FIGS. 3A to 3D are diagrams showing a data overwrite recording operationon a disc;

FIG. 4 is a block diagram showing a main part of a recording andreproducing apparatus according to a first embodiment of the presentinvention;

FIG. 5 is an explanatory diagram showing a sector structure of P-TOC ofa magneto-optical disc;

FIG. 6 is an explanatory diagram showing a sector structure of U-TOC ofa magneto-optical disc;

FIG. 7 is a diagram showing a link structure of U-TOC of amagneto-optical disc;

FIGS. 8A to 8C are diagrams showing a data overwrite recording operationon a disc according to the first embodiment of the present invention;

FIGS. 9A to 9B are diagrams showing an arrangement state of data on adisc before and after an overwrite recording operation according to thefirst embodiment of the present invention;

FIG. 10 shows a management state of U-TOC before the overwrite recordingoperation of the first embodiment according to the present invention;

FIG. 11 shows a management state of U-TOC after the overwrite recordingoperation of the first embodiment according to the present invention;

FIGS. 12A to 12E are diagrams showing another embodiment of the dataoverwrite recording operation on a disc according to the firstembodiment of the present invention;

FIGS. 13A and 13B are diagrams showing a data arrangement state on adisc before and after the overwrite recording operation according to amodification of the first embodiment of the present invention;

FIG. 14 shows a management state of U-TOC before the overwrite recordingoperation according to the modification of the first embodiment of thepresent invention;

FIG. 15 shows a management state of U-TOC after the overwrite recordingoperation according to the modification of the first embodiment of thepresent invention;

FIG. 16 is a flowchart for the data overwrite recording operation on adisc according to the first embodiment of the present invention;

FIGS. 17A to 17D are diagrams showing a data overwrite recordingoperation on a disc according to a second embodiment of the presentinvention;

FIGS. 18A and 18B are diagrams showing a data arrangement state on adisc before and after the overwrite recording operation of the secondembodiment of the present invention; and

FIG. 19 is a flowchart for the data overwrite recording operation on adisc according to the second embodiment of the present invention.

DESCRIPTION OF THE INVENTION

Preferred embodiments of a recording method and a recording apparatusaccording to the present invention will be described in detail withreference to the accompanying drawings. In the following description, arecordable disc-shaped recording medium is representatively used as arecording medium, and first and second embodiments will be described inthis order.

A. FIRST EMBODIMENT

1. Construction of Recording and Reproducing Apparatus

2. P-TOC sector

3. U-TOC sector

4. Area Structure of Disc

5. Example 1 of Overwrite Recording Operation

6. Example 2 of Overwrite Recording Operation

7. Overwrite Recording Processing

B. SECOND EMBODIMENT

8. Example of Overwrite Recording Operation

9. Overwrite Recording Processing

A. FIRST EMBODIMENT

<1. Construction of Recording and Reproducing Apparatus>

FIG. 4 is a block diagram showing a main part of the recording andreproducing apparatus of a first embodiment of the present invention.

FIG. 4 schematically shows a state where a disc-shaped recording mediumsuch as a magneto-optical disc 1 on which audio or sound data arerecorded is loaded from a disc insertion opening which is provided to amain body of the apparatus. The magneto-optical disc 1 is rotationallydriven by a spindle motor 2.

A reference numeral 3 represents an optical head for irradiating a laserbeam onto the magneto-optical disc 1 at the recording and reproducingoperations. At the recording operation, the optical head 3 irradiates alaser beam having high level output power level to heat recording layeror recording tracks of the magneto-optical disc 1 to Curie temperature.At the reproducing operation, the optical head 3 irradiates a laser beamhaving relatively low output power level to detect the audio datarecorded on the magneto-optical disc 1 on the basis of a reflectionlight beam from the magneto-optical disc 1 by Kerr effect.

Therefore, the optical head 3 has a laser diode as a light source, anoptical system containing a polarizing beam splitter, an objective lens3a, etc., and a photodetector for detecting the reflection light beamfrom the magneto-optical disc 1. The objective lens 3a is supported byan actuator 4 so as to be movable in a parallel direction of the opticalaxis of the objective lens 3a and a perpendicular direction of theoptical axis of the objective lens 3a.

A reference numeral 6 represents a magnetic head for generating avertical magnetic field which is modulated according to recording dataand supplying the vertical magnetic field to the magneto-optical disc 1.The magnetic head 6 is disposed so as to face the optical head 3 throughthe magneto-optical disc 1. The optical head 3 and the magnetic head 6are supported by a feed mechanism 5 so as to be movable in a radialdirection of the disc.

Signals which are read out from the magneto-optical disc 1 by theoptical head 3 through the reproducing operation are supplied to an RFamplifier 7. The RF amplifier 7 is supplied the output signal from theoptical head 3 and produces an RF signal, a tracking error signal, afocus error signal, absolute position data (absolute positioninformation which is recorded as a pre-group (wobbling group) on themagneto-optical disc 1, address data, a focus monitor signal, etc. TheRF signal is supplied to an encoder/decoder unit 8. The tracking errorsignal and the focus error signal are supplied to a servo circuit 9. Theaddress data and the absolute position information are supplied to anaddress decoder 10, and the absolute position data and the focus monitorsignal are supplied to a system controller 11 which composed of amicrocomputer, for example.

The servo circuit 9 generates various kinds of servo signals on thebasis of the tracking error signal, the focus error signal and a trackjump instruction, a seek instruction, rotational velocity detection dataof the spindle motor 2, etc. which are supplied from the systemcontroller 11, and controls the actuator 4 and the feed mechanism 5 onthe basis of these signals, thereby performing focus and trackingcontrol. Further, the servo circuit 9 also controls the spindle motor 2to rotate at a constant angular velocity (CAV) or at a constant linearvelocity (CLV).

The RF signal is subjected to decode processing such as EFM decoding,CIRC, etc. in the encoder/decoder 8, and then temporarily stored in abuffer memory 13. The read-out operation of data from themagneto-optical disc 1 by the optical head 3 and the transfer operationof reproduced data in a system including elements from the optical head3 to the buffer memory 13 are performed at 1.41 Mbit/sec andintermittently. The buffer memory 13 composed of a RAM having 4 Mbytestorage capacity, for example.

The data stored in the buffer memory 13 are read out at such a timingthat the reproduced data are transferred at 0.3 Mbit/sec, and suppliedto the encoder/decoder 14. Thereafter, the data supplied to theencoder/decoder 14 is subjected to decoding processing and are output asdigital signals.

The digital signals outputted from the encoder/decoder 14 are convertedinto analog signals by a D/A converter 15, and supplied to an analogline output terminal 16A. Alternately, the digital signals outputtedfrom the encoder/decoder 14 are directly supplied to a digital outputterminal 16D without passing through the D/A converter 15.

The data write/read operation for the buffer memory 13 is carried outwhile a memory controller 12 controls a writing pointer and a readingpointer to indicate an address. The writing pointer (write-in address)is incremented at the timing of 1.41 Mbit/sec as described above, andthe reading pointer (read-out address) is incremented at the timing of0.3 Mbit/sec. As a result, some amount of data are allowed to be stockedin the buffer memory 13 due to the difference between the write-in bitrate and the read-out bit rate. The increment of the writing pointer isstopped at the time when data whose amount corresponds to the maximumstorage capacity of the memory are stocked in the buffer memory 13, andthe data read-out operation from the magneto-optical disc 1 by theoptical head 3 is also stopped. However, the increment of the readingpointer R is continued, so that the data which are output from theoutput terminal 16A or output terminal 16D are continuously outputwithout interruption.

Thereafter, only the read-out operation from the buffer memory 13 iscontinued, and if the data storage amount in the buffer memory 13 isreduced to a predetermined amount or less at a time, the data read-outoperation by the optical head 3 and the increment of the writing pointerare restarted again, and thus the data stock into the buffer memory 13is started.

By outputting the reproduced audio signals through the buffer memory 13as described above, the output of the reproduced audio signals are notinterrupted even when a tracking servo is out of control due to anexternal disturbance or the like. Accordingly, by accessing a scanningposition just before the tracking servo gets out of control andrestarting the data read-out operation from the position while the dataare still stocked in the buffer memory 13, the reproducing operation canbe continued without being disturbed. That is, a vibration-resistantfunction of the recording and reproducing apparatus can be remarkablyimproved.

In FIG. 4, the address information output from the address decoder 10and the subcode data for the control operation are supplied to thesystem controller 11 through the encoder/decoder 8, and used for variouscontrol operations.

The system controller 11 is further supplied with a lock detectionsignal of a PLL circuit for generating a bit clock of therecording/reproducing operation, and a monitor signal indicating a lockstate of a frame synchronizing signal of reproduced data (L,R channels).

The system controller 11 outputs a laser control signal SLP to controlthe operation of the laser diode of the optical head 3, andon/off-controls the output of the laser diode. At the on-control time,the system controller 11 switches the reproducing laser beam havingrelatively low level power and the recording laser beam havingrelatively high level power to each other.

When the data recording operation is performed on the magneto-opticaldisc 1, analog or digital audio signals are supplied from an externalequipment to the recording and reproducing apparatus through aconnection code connected to the analog input terminal 17A, an audiooptical cable connected to the digital input terminal 17D.

The audio signals which are supplied to the digital input terminal 17Din the form of digital signals are directly input to the encoder/decoder14. On the other hand, the analog audio signals which are input to theanalog input terminal 17A are converted into digital signals by an A/Dconverter 18, and then supplied to the encoder/decoder 14.

In the encoder/decoder 14, the input digital signals are performed tothe audio compression encode processing. The digital data which arecompressed by the encoder/decoder 14 are temporarily stored into thebuffer memory 13 by the memory controller 12, and then read out at apredetermined timing and supplied to the encoder/decoder 8. The digitaldata which are output from the encoder/decoder 14 are encoded byprocessing such as the CIRC encode, EFM modulation, etc. by theencoder/decoder 8, and then supplied to a magnetic head driving circuit15.

The magnetic head driving circuit 15 supplies a magnetic head drivingsignal to the magnetic head 6 in accordance with the encoded recordingdata from the encoder/decoder 8. That is, N-pole or S-pole verticalmagnetic field is supplied to the magneto-optical disc 1 by the magnetichead 6. At this time, the system controller 11 supplies a control signalto the optical head 3 to radiate a laser beam having a recording level(high level power).

A reference numeral 19 represents an operational input unit which isprovided with various keys to be manipulated by an user, such asoperation keys for reproduction/quick traverse/quick return/AMSsearch/stop/record, etc., operation keys for setting various operationmodes, and operation keys for performing various edition processing.

A reference numeral 20 represents a display unit composed of a liquidcrystal display, and an operation state, a mode state, a reproductionadvancing time, a record advancing time, a track number, etc. aredisplayed thereon under control of the system controller 11.

When the recording/reproducing operation is performed on themagneto-optical disc 1, the management data recorded on themagneto-optical disc 1, that is, P-TOC (pre-recorded Table Of Contents),U-TOC are read out, and stored into a storage portion of the systemcontroller 11 or an exclusively-used storage portion of the buffermemory 13. In accordance with these management data, the systemcontroller 11 identifies the address of a part to be recorded on themagneto-optical disc 1 or the address of a part to be reproduced. In thefirst embodiment, the management data are stored in an exclusively-usedstorage area of the buffer memory 13. Accordingly, a buffer area forrecording data/reproducing data as described above and an area forholding the management data are sectionally set in the buffer memory 13.

When the magneto-optical disc 1 is loaded into the recording andreproducing apparatus, the system controller 11 executes the reproducingoperation at the innermost side of the disc on which the management dataare recorded, thereby reading out the management data, and then storesthe read-out management data into the exclusively-used storage area ofthe buffer memory 13. Subsequently, the system controller 11 refers tothe management data in the buffer memory 13 when therecording/reproducing operation is carried out on the magneto-opticaldisc 1.

The U-TOC is edited to be rewritten in accordance with the recording ordeletion of the data. The system controller 11 conducts this edition onthe management data of the U-TOC stored in the buffer memory 13 everytime the recording/deleting operation is carried out, and it alsoconducts the rewriting operation on the U-TOC area of themagneto-optical disc 1 at a predetermined timing in accordance with theabove rewriting operation of the management data of the U-TOC.

<2. P-TOC sector>

Here, an audio data sector which is recorded in the form of sector dataon the magneto-optical disc 1 and a P-TOC sector which is managementdata for managing the recording/reproducing operation of the audio datawill be first described.

With the management data of the P-TOC, area indication for recordableareas, etc. on the magneto-optical disc 1, management of U-TOC area,etc. are performed. When a disc loaded into the apparatus is apre-recorded disc which is a read-only disc, pieces of music which arerecorded with pits like a so-called Compact disc can be also managedwith the P-TOC.

FIG. 5 shows a format of the P-TOC, and more particularly it shows onesector (sector 0) of P-TOC information which is repetitively recorded onan area for P-TOC, for example, a unrewritable area at the innermostperipheral side of the disc. The description of a sector 1 andsubsequent sectors thereof in the P-TOC format is omitted.

A data area (4 bytes×588=2352 bytes) of a P-TOC sector is provided, atthe head position thereof, with 4 bytes for a synchronization patterncomposed of one byte data of all "1" or all "0", and an addressrepresenting a cluster address and a sector address, etc. This 4-bytearea constitutes a header, and with this header, it is indicated thatthe area is an area of the P-TOC. Subsequently to the header, anidentification ID of ASCII code which corresponds to a character "MINI"is added at a predetermined address position.

Subsequent to the ID are recorded a disc type representing whether aloaded disc is a recordable disc or a read-only disc (disc usedexclusively used for reproduction), a recorded sound level or recordinglevel, the number of the first piece of music recorded (First TNO), thenumber of the last piece of music recorded, a read-out start addressRO_(A), a power calibration area start address PC_(A), a start addressUST_(A) of U-TOC (a data area of U-TOC sector 0 of FIG. 6 as describedlater), a start address RST_(A) of a recordable area (recordable userarea), etc.

Subsequently to the above areas is provided a corresponding tableindicating data portion having table pointers (P-TNO1 to P-TNO255) withwhich respective pieces of music recorded are allowed to correspond topart tables of a management table portion as described later.

The management table portion having 255 part tables from (01h) to (FFh)which are provided in correspondence with the table pointers (P-TNO1 toP-TNO255) of the corresponding table indicating data portion is providedon an area subsequent to the corresponding table indicating dataportion. In this specification, a numerical value affixed with "h" isrepresented with hexadecimal notation. Each of the part tables isdesigned to be recordable with a start address serving as a start pointfor a part, an end address serving as an end point for the part and modeinformation for the part (track). The term "part" means a track portionon which those data which are continuous on time axis are recordedphysically continuously, and for example, M₁ and M₄(4) as shown in FIG.1 correspond to track portions.

The mode information of a track in each part table means information asto whether the part is set to a rewrite-inhibition mode or a datacopy-inhibition mode, information as to whether it is audio information,information on classification of monaural/stereo, etc.

With respect to the respective part tables from (01h) to (FFh) in themanagement table portion, the contents of the parts (part tables) arerepresented with the table pointers (P-TNO1 to P-TNO255) of thecorresponding table indicating data portion. That is, with respect tothe first piece of music, a part table (for example, (01h) is recordedas a table pointer P-TNO1 (However, a numerical value which canrepresent the part table with its byte position in the P-TOC sectorthrough predetermined calculation processing is actually written in thetable pointer) is recorded as a table pointer P-TNO1. In this case, thestart address of the part table (01h) is a start address at therecording position of the first piece of music, and likewise the endaddress thereof is an end address at the position at which the firstpiece of music is recorded. The mode information of the track is theinformation on the first piece of music.

Likewise, with respect to the second piece of music, the start and endaddresses of the recording position of the second piece of music and themode information of the track are recorded in the part table (forexample, (02h)) which is represented by the table pointer P-TNO2.

With the table pointers, the table pointers of 255, from (P-TNO1) to(P-TNO255), are prepared, and thus 255 pieces of music can be managed onthe P-TOC. As described above, by forming the sector 0 of the P-TOC, adesired piece of music can be accessed and reproduced at the reproducingtime.

With respect to a recordable/reproducible magneto-optical disc, thereexists no pre-recorded music area thereon. Therefore, the correspondingtable indicating data portion and the management table portion asdescribed above are not used, and these are managed by an U-TOC asdescribed layer. Accordingly, all of the bytes are set to "00h".

However, with respect to a pre-recorded type disc on which all pieces ofmusic are recorded in the form of pits and a hybrid type disc havingboth a read-only area (area which is used exclusively for reproductionand on which pieces of music, etc. are recorded) and a recordable areacomposed of a magneto-optical area, the corresponding table indicatingdata portion and the management table portion as described above areused to manage the pieces of music in the read-only area.

<3. U-TOC sector>

Next, U-TOC will be described below.

FIG. 6 shows the format of a sector (sector 0) of U-TOC, and this sectormainly contains a data area having management data for pieces of musicwhich have been recorded by an user, and unrecorded areas (free areas)on which new pieces of music can be recorded. The sector 1 andsubsequent sectors of the U-TOC are also optional, and the descriptionthereof is omitted.

For example, when a piece of music is recorded on the disc 1, the systemcontroller 11 searches a free area on the disc 1 on the basis of themanagement data of the U-TOC to record audio data on the searched freearea. At the reproduction time, the system controller 11 identifies, onthe basis of the management data of the U-TOC, an area on which a pieceof music to be reproduced is recorded, and accesses the area to performthe reproducing operation.

Like the P-TOC, the sector (sector 0) of the U-TOC is provided with aheader at the head position, and subsequently provided with data on amaker code, a model code, the number of the first piece of music (FirstTNO), the number of the last piece of music (Last TNO), a sector usestate, the serial number of the disc, a disc ID, etc. at predeterminedaddresses. On the sector 0 of the U-TOC are further provided areas onwhich various table pointers (P-DFA, P-EMPTY, P-FRA, P-TNO1 to P-TNO255)are recorded as the corresponding table indicating data portion. Withthese table pointers, recording areas for pieces of music which arerecorded by the user, non-recording areas, etc. are allowed tocorrespond to a management table portion as described above to therebyidentify these areas.

255 part tables of (01h ) to (FFh) are provided for the management tableportion to which the table pointers (P-DFA to P-TNO255) of thecorresponding table indicating data portion are allow to correspond.Like the sector 0 of the P-TOC as shown in FIG. 5, each part table isrecorded with a start address serving as a start point for a part, anend address serving as an end point for the part, and the modeinformation for the part. Furthermore, with respect to the U-TOC sector0, in some cases a part which is indicated by each part table iscontinuously linked to another part. Accordingly, the part table isfurther recorded with link information representing a part table onwhich the start address and the end address of the part to be linked arerecorded.

In this type of recording and reproducing apparatus, no trouble wouldoccur because the reproducing operation proceeds while successivelyaccessing parts even if the music data of a piece of music are recordedphysically discontinuously, that is, divisionally recorded over pluralparts. Therefore, with respect to pieces of music, etc. which arerecorded by the user, in some cases the user dares to record a piece ofmusic while dividing the music data of the piece of music into pluralparts for the purpose of effective use of the recordable areas.Therefore, the link information to link the respective parts to eachother is provided. For example, part tables to be linked to one anotherare indicated with numbers (01h) to (FFh) which are given to therespective part tables (actually, represented by numeral values each ofwhich corresponds to the byte position in the U-TOC sector 0 through thepredetermined calculation processing), and then linked to one another.With respect to the music data of piece of music, etc. which arebeforehand recorded in the form of pits, the link information of all thepart tables is set to "(00h)" in the P-TOC sector 0 as shown in FIG. 5,because these music data are not divided into parts in normal cases.

That is, in the management table portion in the U-TOC sector 0, one parttable represents one part. For example, for a piece of music which isconstructed by linking three parts to one another, the part position ofthe piece of music is managed by the three linked part tables.

The part content of each of the part tables from (01h) to (FFh) in themanagement table portion of the U-TOC sector 0 is indicated as followswith the table pointers (P-DFA, P-EMPTY, P-FRA, P-TNO1 to P-TNO255) ofthe corresponding table indicating data portion.

The table pointer P-DFA indicates a defective area on themagneto-optical disc 1, and specifies a part table or a part table atthe head of plural part tables in which a track portion (part) servingas a defective area due to scratch or the like is indicated. That is,when a defective part exists, any one of (01h) to (FFh) is recorded inthe table pointer P-DFA, and the defective part is indicated with thestart and end addresses in the corresponding part table. If anotherdefective part exists, another part table is indicated as linkinformation for the former part table, and the defective part is alsoindicated in the part table. If no other defective parts exist, the linkinformation is set to "(00h)" for example, and it is indicated thatthere is no defective part to be subsequently linked.

The table pointer P-EMPTY specifies an unused part table or one ofplural unused part tables in the management table portion. If an unusedpart table exists, any one of (01h) to (FFh) is recorded as the tablepointer P-EMPTY. If plural unused part tables exist, these part tablesare successively indicated from a part table indicated by the tablepointer P-EMPTY with the link information, and all the unused parttables are linked to one another on the management table portion.

The table pointer P-FRA indicates a data rewritable free area(containing a deletion area) on the magneto-optical disc 1, andspecifies a part table or one of plural part tables on which a trackportion (part) serving as a free area is indicated. That is, if a freearea exists, any one of (01h) to (FFh) is recorded in the table pointerP-FRA, and the part serving as the free area is specified with the startand end addresses in the corresponding part table. If there exist aplurality of such parts, that is, part tables, the part tables aresuccessively indicated with the link information until the indicationreaches a part table having link information of"(00h)".

FIG. 7 schematically shows a management state of parts serving as freeareas with part tables. This represents a state that when parts(03h)(18h)(1Fh)(2Bh)(E3h) are set as free areas, this state isrepresented by the link of the part tables (03h)(18h)(1Fh)(2Bh)(E3h).The same is satisfied for the management mode for the defective areas asdescribed above and the unused part tales.

If no audio data of pieces of music are recorded and no defect exists onthe magneto-optical disc, the part table (01h) is indicated by the tablepointer P-FRA, whereby the whole recordable user area on the disc isindicated to be an unrecorded area (free area). In this case, theremaining part tables of (02h) to (FFh) are not used. Therefore, thepart table (02h) is indicated by the table pointer P-EMPTY as describedabove, the part table (03h) is indicated with the link information ofthe part table (02h), and the part table (04h) is indicated with thelink information of the part table (03h). This linking indication iscontinued until it reaches the part table (FFh). In this case, the linkinformation of the part table (FFh) is set to "(00h)" which representsno subsequent linkage.

At this time, for the part table (01h), the start address of therecordable user area is recorded as a start address, and the addressjust before the read-out start address is recorded as an end address.

The table pointers P-TNO1 to P-TNO255 indicate pieces of music which theuser have recorded on the magneto-optical disc 1. For example, the tablepointer P-TNO1 specifies a part table indicating a part or one of pluralparts at the head position on time on which the music data of the firstpiece of music are recorded.

For example, when the music data of the first piece of music arerecorded while the track is not divided into plural parts, that is, themusic data are recorded on one part, the recording area of the firstpiece of music is recorded as the start and end addresses in the parttable indicated by the table pointer P-TNO1.

For example, when the music data of a second piece of music arediscretely recorded over plural parts on the disc, parts for indicatingthe recording position of the music data are specified in time order.That is, on the basis of a part table indicated by the table pointerP-TNO2, other part tables are successively indicated in time order withlink information, and this linkage is continued until a part tablehaving link information of "(00h)" (in the same mode as FIG. 7). Asdescribed above, all the parts on which the data constituting the secondpiece of music are recorded are successively indicated, and thus whenthe second piece of music is reproduced or the data overwrite operationis performed on the area of the second piece of music, the optical head3 and the magnetic head 6 are actuated to access to take out music datafrom the discrete parts or record the music data with effective use ofthe recording area by using the data of the U-TOC sector 0.

As described above, the areas on the disc are managed by the P-TOC, andthe music data recorded on the recordable user area, the free areas,etc. are managed by the U-TOC. These TOC data are read and stored intothe buffer memory 13, and the system controller 11 can refer to thesedata.

<4. Area Structure of Disc>

Next, the structure of the recording area of the disc will be described.FIG. 8A schematically shows the structure of the recording area of thedisc in the radial direction of the disc.

In the magneto-optical disc 1, the recording area is mainly classifiedinto an area (pre-recorded area) which is represented as a pit area inFIG. 8A and on which data are recorded with embossed pits, and a groovearea serving as a data recording area which is provided with grooves.

The P-TOC as described above is repetitively recorded on the pit area.As described above, in the P-TOC, the position of the U-TOC isrepresented as the U-TOC start address UST_(A), and the respectivepositions shown in FIG. 8A are represented as a start address RO_(A) ofthe read-out, a start address RST_(A) of the recordable user area, astart address PC_(A) of the power calibration area, etc.

The groove area is formed subsequently to the pit area at the innermostperipheral side of the disc. In the groove area, an area which extendsto the address represented as the start address RO_(A) of the read-outin the P-TOC is allocated as a recordable user area, and an areasubsequent to the read-out start address RO_(A) is allocated as aread-out area.

Of the recordable area, a recordable user area on which data areactually recorded extends from the start address RST_(A) of therecordable user area to the position just before the start addressRO_(A) of the read-out.

An area before the start address RST_(A) of the recordable user area inthe groove area is used as a management area for the recording andreproducing operation, and the U-TOC as described above, etc. arerecorded on this area. One cluster is further provided from the positionrepresented by the start address PC_(A) of the power calibration area,and this cluster is used as a calibration area for a laser beam, thatis, a trial recording area for setting the output power level of thelaser beam.

The U-TOC is continuously recorded by the amount corresponding to threeclusters (1 cluster=36 sectors) from the position which is representedby the U-TOC start address UST_(A) in the management area for therecording and reproducing operation.

Actual audio data are recorded on the recordable user area as shown inFIG. 8A. For example, for the music data M₁ to M₄ of four pieces ofmusic, the music data M₁ of the first piece of music is recorded on apart between addresses A₀ and A₁, the music data M₂ of the second pieceof music is recorded at a part between addresses A₂ to A₃, the musicdata M₃ of the third piece of music is recorded on a part betweenaddresses A₄ to A₅, and the music data of the fourth piece of music isrecorded at a part between addresses A₆ to A₇. In this state, a freearea on which music data have not yet been recorded is set as a partbetween addresses A₈ and A₉. Such a recording state is managed by thetable pointers P-TNO1 to P-TNO4, P-FRA and the part tables linkedthereto in the U-TOC as described above. The management state in thiscase is shown in FIG. 10. Assuming that the recordable user area in FIG.8A has no defect, the table pointer P-DFA is set to "00h".

In order to manage an unrecorded area (free area), for example when apart table of (05h) is indicated in the table pointer P-FRA, informationon the part serving as the free area in FIG. 8A is indicated in the parttable of (05h) in correspondence to the indication in the table pointerP-FRA. That is, the address A₈ is indicated as the start address, andthe address A₉ is indicated as the end address. In this case, since nofree areas serving as other parts exist, the link information of thepart table (05h) is set to "00h".

With the music data M₁ of the first piece of music, the start address A₀and the end address A₁ thereof are indicated in the part table of (01h)which is indicated in the table pointer P-TNO1. The music data M₁ isrecorded on one part, so that the link information of the part table(01h) is set to "00h".

With the second music data M₂, the third music data M₃ and the fourthmusic data M₄, the part positions thereof are managed by the part tableswhich are obtained from the table pointers P-TNO2, P-TNO3 and P-TNO4 asstart points, respectively. In this case, only four pieces of music arerecorded, and thus the table pointers P-TNO5 to P-TNO255 are not used,so that the link information is set to "00h".

In this case, the table pointer P-EMPTY for indicating unused parttables indicates a part table of (06h), and all unused part tables fromthe part table (06h) to the part table (FFh) are linked to one anotherwith the link information.

<5. Example 1 of Overwrite Recording Operation>

An operation of overwriting data on the magneto-optical disc 1 using therecording and reproducing apparatus of this embodiment, for example whenthe music data M₁ to M₄ are recorded on the magneto-optical disc asshown in FIG. 8A, will be described with reference to FIGS. 8A to 11.

As described above, the recording state of FIG. 8A is managed accordingto such a format as show in FIG. 10. In this case, a data arrangement onthe disc which is developed on a reproduction time axis is shown in FIG.9A. That is, when the reproduction is performed on the disc, the piecesof music (M₁ to M₄) are successively reproduced in this order, and theproducing operation is finished at the time when the rendition of thepiece of music (M₄) is completed.

Now, it is assumed that the user starts the recording operation on thedisc at the time when the reproduction proceeds to the head position ofthe second piece of music M₂ on time axis (which physically correspondsto the address A₂). In this case, first, the system controller 11 startsthe data deleting operation from the address A₂ as shown in FIG. 8B, anddetects the head of the free area on the basis of the management data ofthe U-TOC to start the data recording operation on a free area, that is,an area which extends from the address A₈ to subsequent addresses inFIG. 8B.

For example, data of one cluster are deleted from the address A₂, anddata of one cluster are subsequently recorded from the address A₈.Subsequently, in the same manner as described above, the past data ofthe piece of music (M₂) of one cluster are further deleted subsequent tothe area which was deleted in the previous deleting operation, and atthe same time data of one cluster are recorded on the free areasubsequent to the area which was recorded in the previous recordingoperation. That is, each of the deleting and recording operations isrepetitively performed one cluster by one cluster.

When the above recording operation is continued, the time length of therecording data in the free area becomes equal to the time length of thedata deleted portion in the area for the music data M₂ as indicated by ahatched portion of FIG. 8B.

The deleting operation is carried out in the edition processing of theU-TOC in the buffer memory 13, that is, such edition processing that thearea for the past music data M₂ is enrolled into the free area from theaddress A₂ on cluster basis. As described later, the management data ofthe U-TOC after the edition processing is performed are written into theU-TOC on the disc 1.

At the time when the data have been just recorded on an area extendingfrom the address A₈ to A₁₀ as shown in FIG. 8C, the past data recordedon the area for the music data M₂ have been just deleted within areproduction time position range having the same time length as the datawhich have been just recorded on the free area, that is, the past datawithin an area extending from the address A₂ to A₁₁ have been justdeleted, and this deleted area is enrolled into the free area andmanaged on the U-TOC.

If the recording stop is instructed through the operation input unit 19at this time, the recorded data are set as new music data M₂, and thepast music data M₂ are deleted. The new music data M₂ are managed on theU-TOC. With respect to the music data M₃, a portion of the music data M₃which extends from the address A₄ to the address A₁₁ are deleted,however, the other portion extending from the address A₁₃ to the addressA₆ remains. In addition, the whole music data M₄ remains. Therefore, thedata recording state on the reproduction time axis after the aboverecording operation is completed is shown in FIG. 9B. That is, only thepast data are deleted by the same amount as the newly recorded musicdata M₂ (i.e., the past music data M₂ and the first half of the musicdata M₃ are deleted). Accordingly, the user can recognize the recordingstate on the disc after a new piece of music is recorded as if heoverwrote it on a compact cassette tape.

At the time when the recording operation is completed, the U-TOC isrewritten as shown in FIG. 11. That is, the table pointer P-TNO2indicating the music data M₂ indicates the part table (06h), and thestart address A₈ and the end address A₁₀ are indicated in the part table(06h). Furthermore, the addresses A₂ to A₁₁ are written as a free areain the part table (07h) which is linked from the part table (05h). Thestart address of the music data M₃ is set as an address A₁₃ in the parttable (03h). The above edition leaves the part table (02h) unused, sothat it is enrolled into the linkage from the table pointer P-EMPTY. Thedata recorded on the disc are managed on the U-TOC as described above,so that the respective pieces of music (the music data M₁, the new musicdata M₂, the remaining portion of the music data M₃, the music data M₄)are successively reproduced in this order as shown in FIG. 9B.

The edited state (format) of the U-TOC after the recording operation asdescribed above is completed is not limited to the state (format) shownin FIG. 11. For example, the part tables to be used after the edition,the data-rewritten portion, the link order for the free areas or unusedpart tables, etc. are dependent on an edition processing software whichis installed into the system controller 11. For example, the concretedata-rewritten portion of the U-TOC for managing the state of FIG. 9Bmay be set to a portion different from that shown in FIG. 11.Accordingly, FIG. 11 shows an example of the state after the edition.

<6. Example 2 of Overwrite Recording Operation>

Next, an operation of overwriting data on the magneto-optical disc 1using the recording and reproducing apparatus of this embodiment whenmusic data M₁ to M₃ are recorded as shown in FIG. 12A will be describedwith reference to FIGS. 12A to 15.

In this case, each of the music data M₁ to M₃ composed of plural parts,and each of the respective music data M₁ to M₃ is discretely recordedwhile being divided into plural parts (the music data M₁ are dividedinto parts M₁(1) and M₁(2), the music data M₂ is divided into partsM₂(1) and M₂(2), and the music data is divided into parts M₃(1), M₃(2)and M₃(3).

This recording state is managed on the U-TOC as shown in FIG. 14, forexample.

First, the data management of the first music data M₁ is performed asfollows. The start address A₂₇ and the end address A₂₈ of the part M₁(1)are indicated in a part table (01h) which is indicated in a tablepointer P-TNO1, and the start address A₃₇ and the end address A₃₈ of thepart M₁(2) are indicated in a part table (03h) which is subsequentlylinked to the part table (01h). Accordingly, the addresses of each partand the order on the reproduction time axis are managed as describedabove.

The data management of the second music data M₂ is performed as follows.A part table (04h) in which the start and end addresses A₂₃ and A₂₄ ofthe part M₂(1) are indicated is linked from a table pointer P-TNO2, anda part table (02h) in which the start and end addresses A₂₉ and A₃₀ ofthe part M₂(2) is linked from the part table (04h).

The data management of the third music data M₃ is performed as follows.A table pointer P-TNO3, a part table (05h), a part table (06h) and apart table (07h) are successively linked to one another in this order,and the addresses of each part M₃(1), M₃(2), M₃(3) and the time orderare managed.

There are three parts as free areas in FIG. 12A. These parts are alsomanaged by successively linking a table pointer P-FRA, a part table(08h), a part table (09h) and a part table (0Ah) to one another in thisorder.

If the physical recording state shown in FIG. 12A is shown in terms ofthe arrangement state of data recorded on the disc in the reproductiontime axis direction, it corresponds to the state shown in FIG. 13A. Whenthe reproducing operation is carried out on this disc, the music data M₁to M₃ are successively reproduced in this order, and the reproducingoperation is finished at the rendition end time of the music data M₃.

Now, it is assumed that the user starts the recording operation at thetime when the reproducing operation proceeds to the head position of thepart M₂(2) (physically, address A₂₉) which corresponds to a position onthe reproduction time axis (time) in the middle of the second piece ofmusic (M₂). In this case, the system controller first deletes data fromthe address A₂₉ as shown in FIG. 12B, and detects the head of a freearea on the basis of the management data of the U-TOC to start therecording operation of the free area from the address A₃₉.

That is, the data deletion of one cluster and the data recording of onecluster on the free area are repeated on the part M₂(2) using theseaddresses as start points. Accordingly, as indicated by a hatchedportion of FIG. 12B, the time length of the data recorded on the freearea is equal to the time length of the data-deleted portion of the areafor the music data M₂.

Here, after the recording operation is continued and all the addressesA₂₉ to A₃₀ for the part M₂(2) are deleted, an area which is continuouswith the part M₂(2) on the reproduction time axis, that is, the headpart M₃(1) of the third music data M₃ is deleted. Physically, thedeletion of the recorded data is started from the address A₂₅ subsequentto the deletion of the recorded data until the address A₃₀.

For example, at the time when new data are recorded on an area extendingfrom an address A₃₉ to an address A₄₀ as shown in FIG. 12D, data in areproduction time position range having the same time length or samedata amount as the newly-recorded data, that is, in this case, the datawhich have been already recorded within the area between the addressesA₂₉ and A₃₀ and within the area between the addresses A₂₅ and A₂₆ aredeleted with the address A₂₉ set as a deletion start point, and thesedata-deleted portions are enrolled as a free area and managed on theU-TOC.

Assuming that the recording operation is stopped through the operationinput unit 19 at this time, through the edition processing of themanagement data of the U-TOC, the data recording state is managed asshown in FIG. 12E if it is viewed in terms of the physical position onthe disc, or it is equivalent to a state shown in FIG. 13B if it isviewed on the reproduction time axis.

That is, the data which are newly recorded in the present recordingoperation are set as the music data M₃, and the old music data M₂ whichhave been recorded on the magneto-optical disc 1 before the presentrecording operation are newly set as the music data M₂ having only thefirst half part M₂(1) of the old music data M₂ (i.e., the other part ofthe music data M₂ is deleted). With respect to the old music data M₃,the part M₃(1) is deleted while only the parts M₂(2) and M₃(3) remain,however, the remaining parts of the old music data M₃ are managed asfourth music data M₄ because the newly-recorded data are managed as themusic data M₃.

Accordingly, at the time when the recording operation is completed, theU-TOC is rewritten as shown in FIG. 15. That is, the music data M₂ isset as a single part which is not linked to another part, and whosestart and end addresses A₂₅ and A₂₄ are indicated in the part table(04h) which is indicated by the table pointer P-TNO2. With respect tothe new music data M₃, the start address A₃₉ and the end address A₄₀thereof are written in the part table (08h) indicated by the tablepointer P-TNO3.

Furthermore, the parts of the addresses A₂₉ and A₃₀ and the addressesA₂₅ and A₂₆ on which the data are deleted are written as free areas inthe part tables (02h) and (05h) which are linked from the part table(0Ah).

Still furthermore, the remaining parts (M₃(2), M₃(3)) of the old musicdata M₃ which have been recorded before the present recording operationare indicated as parts M₄(1) and M₄(2) of new music data M₄ by thelinkage from the table pointer P-TNO4 through the part table (06h) tothe part table (07h).

The above state after the edition is an example, and thus the concreterewriting portion is dependent on the software.

<7. Overwrite Recording Operation>

The two examples of the overwriting operation of the first embodimentare described above, and the processing of the system controller 11 forthe overwrite recording operation as described above will be describedwith reference to a flowchart of FIG. 16.

When the recording start operation is instructed through the operationinput unit 19, only the past data (data recorded on the disc 1) of onerecording unit are deleted from the reproduction time position (F102).In this embodiment, one recording unit corresponds to one cluster, andthus the past data of one cluster are deleted.

Subsequently, the process waits until data of one cluster are stocked inthe buffer memory 13 (F104), and then data of one cluster are recordedon a free area at the time when the data are stocked. Basically, theabove operation is repeated to perform a recording operation of newdata.

However, in some cases, a track jump may occur due to vibration appliedto the recording and reproducing apparatus, so that the optical head 3and the magnetic head 6 cannot perform a proper recording operation. Inthis case, the process goes from step F103 to F106, and returns to stepF102 again to further delete data of one cluster. Thereafter, at thetime when data of one cluster are stocked, data of two clusterscontaining the data which cannot be recorded are recorded (F104, F105).That is, the execution of the recording operation is delayed until therecording and reproducing apparatus is allowed to perform the recordingoperation, and the data are collectively recorded. The following methodsmay be used to detect whether a track jump occurs due to vibration orthe like during the recording operation.

One method is that a vibration sensor is provided in the recording andreproducing apparatus, and the system controller detects occurrence ofthe track jump on the basis of the detection output of the vibrationsensor. The other method is that continuity of the address data outputfrom the address decoder 10 is monitored by the system controller andthe occurrence of the track jump is detected when discontinuity of theaddress data is detected by the system controller. Of course, the abovemethods may be used in combination, and other various methods may beused in place of the above methods.

There is a possibility that the data in the buffer memory 13 overflowsbecause the unrecordable state is kept for a long time, the process goesfrom step F106 to F107 to discard one-cluster data from old data.

Thereafter, when the recording stop operation is instructed through theoperation input unit 19 or from the system controller 11, the processgoes from F101 to F108 so that U-TOC data which have been edited andheld in an exclusively-used area in accordance with the recording anddeleting operation in the buffer memory 13 until that time are writtenon the disc 1 as new management data of U-TOC to thereby renew themanagement data of U-TOC, and then the recording operation is finished.Through the above operation, the overwrite recording operation isperformed.

As described above, a data portion which is to be deleted and has thesame time length of recording data is deleted through the overwriterecording operation while the recording data are recorded on a free areaof the magneto-optical disc 1, so that the user can sensitively andeasily recognize the portion to be deleted. Therefore, this isconvenient for user's use. Furthermore, the processing of trash areascan be easily performed. That is, in the case of the disc system inwhich continuous data on time axis are discretely recorded on themagneto-optical disc 1, a trash area which is not managed by the U-TOCoccurs through the repetitive recording/deleting operation, and thus therecordable time of the disc 1 is reduced by the amount corresponding tothe trash area thus formed. In this case, by enrolling the trash areainto the free area at the data deletion time, the trash area can berestored without complicated edition or calculation processing.

Furthermore, only the data deletion of one cluster is performed as theedition processing at the recording start time, and thus it isunnecessary to carry out an edition or calculation operation fordeleting all the data subsequent to the recording start point.Therefore, the system can be quickly shifted to the actual recordingprocessing.

B. SECOND EMBODIMENT

<8. Example of Overwrite Recording Operation>

Next, the overwrite recording operation in the second embodiment of thepresent invention will be described below. The recording and reproducingapparatus and the management mode of the recording data of thisembodiment are identical to those of the first embodiment, and thedescription thereof is omitted.

For example, assuming that the recording operation on the disc isstarted from the position on the reproduction time axis in the middle ofthe music data M₂, the actual data recording is performed on a free areaas shown in FIG. 17B. If the user instructs the stop operation at thetime when the data of n clusters are recorded, data of n clusters whichhas the same data amount or the same time length as the data to be newlyrecorded are deleted from the position on the reproduction time axis inthe middle of the music data M₂, and this data-deleted area is set as afree area.

At the time when the recording operation is finished, the newly-recordeddata are set as the music data M₂ as shown in FIG. 17D. A reproductiontime position range corresponding to the time length of the data whichhave been newly recorded on the free area from the reproduction timecorresponding to a position in the middle of the old music data M₂(until the old music data M₃) is set as a free area. The remainingportion of the old music data M₃ is managed as music data M₄ on theU-TOC.

Accordingly, if the recording state of the magneto-optical disc 1 isviewed on the reproduction time axis, the recording state shown in FIG.18A before the recording operation is performed is changed to the stateshown in FIG. 18B after the recording operation. That is, on thereproduction time axis, only the past data at the newly overwrittenportion are deleted like the first embodiment.

The second embodiment differs from the first embodiment in that afterdata are temporarily recorded on a free area, the time position rangefrom a reproduction time position at which the recording operation isinstructed is deleted in accordance with the recording time length.

The data deletion is carried out along the direction of the reproductiontime position on the magneto-optical disc 1. Accordingly, when a rangeon which the data deletion is carried out is over plural parts shown inFIGS. 9A to 9D in the first embodiment, a next deletion operation iscarried out from a part which is not linked according to its physicalorder, but linked according to its order on the reproduction time axis,and this is the same as the first embodiment.

<9. Overwrite Record Processing>

The processing of the system controller 11 when the overwrite recordingoperation of the second embodiment will be described with reference to aflowchart of FIG. 19.

When the recording start operation is instructed through the operationinput unit 19, the process waits until data of one cluster are stockedin the buffer memory 13 (F203). At the time when the data of one clusterare stocked, the recording operation of data of one cluster on a freearea is started (F204). That is, this point is identical to a normalrecording processing when no overwrite is carried out, and itcorresponds to the operation shown in FIG. 17B. Accordingly, a softwarefor a free-area recording processing with no overwrite is usable.

When the record stop instruction is made through the operation inputunit 19 or from the system controller 11, the process goes from stepsF201 to F206 and the U-TOC is rewritten to delete the past data havingthe same time length as the data which are newly recorded on the disc 1from the reproduction time position on the disc, which is a start pointfor the recording operation and at which the recording operation isstarted or instructed. That is, the operation shown in FIG. 17C isexecuted. Thereafter, the management data of the U-TOC, the edition forwhich is completed in the exclusively-used area of the buffer memory 13,is written as new U-TOC management data to renew the management data ofthe U-TOC, and the recording operation is finished. With this operation,the overwrite recording operation as described above is realized.

It would be originally possible because of the overwrite recordingoperation that data whose time length is larger than the size of a freearea existing before the recording operation are recorded by recordingdata on a data-deleted portion. However, in the system of deleting thedata after the recording operation as described above, the recordingcannot be performed at the time when the free area existing before therecording operation is completely used. This is because the data on theoverwrite portion are not deleted.

Accordingly, when it is judged that the recording operation cannot beperformed because the free area is completely used, the past data whosedata amount corresponds to the clusters of the new data which have beenrecorded until this time are deleted in the time position direction fromthe reproduction time position (start point) when the recording startoperation on the magneto-optical disc 1 is carried out, thereby forminga free area (F202, F205). Of course, when this processing is carriedout, as the data deletion processing of step F206, the data are deletedby the amount corresponding to the time length of the data which havebeen newly recorded after the deletion operation of step F205 until theend of the recording operation are deleted from the reproduction timeposition (start point) just subsequent to the deleted range of stepF205. Therefore, it is needless to say that the amount of thenewly-recorded data is equal to that of the deleted data in view of thetotal data amount in the recording operation. Therefore, the secondembodiment has the same effect as the first embodiment.

In the embodiments as described above, the recording and reproducingapparatus using the disc-shaped recording medium is representativelyused. However, the effect of this invention can be obtained for anapparatus exclusively used for recording. Furthermore, this invention isnot limited to the recording apparatus using the disc-shaped recordingmedium, and a recording apparatus using another type of disc or a tapeas a recording medium may be used.

What is claimed is:
 1. A recording method for a recording medium, therecording medium having a data recording area on which data are recordedand a management data area on which management data are recorded so asto manage a data recorded area and a data recordable area of the datarecording area, comprising the steps of:when new data are to beover-written on already-recorded data of the recording medium, moving arecording head to a position of the recordable area on the basis of themanagement data which are recorded on the management data area;recording the new data to the recordable area, starting at the positionto which the recording head has been moved; measuring the amount of thenew data to be recorded on the recordable area; and editing themanagement data to delete an amount of the already-recorded data in anamount equal to that of the new data.
 2. The recording method as claimedin claim 1, wherein the management data is edited before the new dataare recorded on the data recordable area.
 3. The recording method asclaimed in claim 1, wherein the management data is edited after the newdata are recorded on the data recordable area.
 4. The recording methodas claimed in claim 3, whereinif the new data cannot be recorded on thedata recordable area due to an amount of the new data being greater thana capacity of the data recordable area, an amount of the new data inexcess of the capacity of the data recordable area is overwritten to thealready-recorded data.
 5. The recording method as claimed in claim 1,wherein the step of editing the management data comprises the stepsof:rewriting management data on the management data area by which thenew data recorded through the recording operation of the new data aremanaged with a same number as the reproduction order of the deletedalready-recorded data when the position at which the recording operationis instructed to start corresponds to the head position of thealready-recorded data on the recording medium; and rewriting themanagement data on the management data area so that the new data aremanaged with a number subsequent to the number of the already-recordeddata, when the already-recorded data are deleted from its midway portionthereof, when the position at which the recording operation isinstructed to start corresponds to a position in the middle of thealready-recorded data.
 6. A recording method for a recording medium, therecording medium having a data recording area on which data are recordeddiscretely and a management data area on which management data arerecorded so as to manage a data recorded area and a data recordable areaof the data recording area, comprising the steps of:when new data areoverwritten on already-recorded data of the recording medium, moving arecording head to a position of the recordable area on the basis of themanagement data which are recorded on the management data area;recording the new data to the recordable area starting at the positionto which the recording head has been moved; measuring the amount of thenew data to be recorded on the recordable area; and editing themanagement data to delete an amount of the already-recorded data in anamount equal to that of the new data.
 7. The recording method as claimedin claim 6, wherein the management data is edited before the new dataare recorded on the data recordable area.
 8. The recording method asclaimed in claim 7, wherein the already-recorded data are deleted sothat the amount of the already-recorded data to be deleted is largerthan the new data to be recorded on the free data recordable area whenit is judged that the new data cannot be contiguously recorded on thefree data recordable area.
 9. The recording method as claimed in claim6, wherein the management data is edited after the new data are recordedon the data recordable area.
 10. The recording method as claimed inclaim 9, whereinif the new data cannot be recorded on the datarecordable area due to an amount of the new data being greater than acapacity of the data recordable area, an amount of the new data inexcess of the capacity of the data recordable area is overwritten to thealready-recorded data.
 11. The recording method as claimed in claim 6,wherein the step of editing the management data comprises the stepsof:rewriting management data on the management data area by which thenew data recorded through the recording operation of the new data aremanaged with a same number as the reproduction order of the deletedalready-recorded data when the position at which the recording operationis instructed to start corresponds to the head position of thealready-recorded data on the recording medium; and rewriting themanagement data on the management data area so that the new data aremanaged with a number subsequent to the number of the already-recordeddata deleted from its midway portion thereof, when the position at whichthe recording operation is instructed to start corresponds to a positionin the middle of the already-recorded data.
 12. A recording apparatusfor a recording medium which has a data recording area on which data arerecorded and a management data area on which management data arerecorded so as to manage a data recorded area and a data recordable areaof the data recording area, said apparatus comprising:recording meansfor recording data on the recording medium; storing means fortemporarily storing inputted data to be recorded on the recordingmedium; encoder means for encoding data read out from said storing meansinto recording data and supplying the encoded data to said recordingmeans; and control means for controlling the operation of said recordingmeans, the storing means and the encoder means, wherein when new dataare to be overwritten on the already-recorded data of the recordingmedium, the control means controls the recording means to access thedata recordable area on the basis of the management data which arerecorded on the management data area, to record the new data to the datarecordable area where the recording means has accessed, and to edit themanagement data to delete the already-recorded data in an amount equalto that of the new data to be recorded on the data recordable area. 13.The recording apparatus as claimed in claim 12, wherein if said controlmeans judges that at least a portion of the new data cannot be recordedon the free data recordable area of the recording medium, said controlmeans controls said storing means to delete the already-recorded datastarting from the position on the data recording area of the recordingmedium corresponding to the state at which the recording operation ofthe new data is instructed to start, before the new data are recorded onthe recordable area.
 14. The recording apparatus as claimed in claim 13,wherein said control means controls said recording means to delete thealready-recorded data from the position corresponding to the state atwhich the recording operation of the new data is instructed to start, bythe same data amount as the new data which have been already recorded onthe recordable area of the recording medium.
 15. The recording apparatusas claimed in claim 13, wherein said apparatus further comprises:memorycontrol means for controlling the write-in and/or read-out operation ofsaid storing means so that the data are read out from said storing meansat a read-out speed which is higher than a write-in speed of data to berecorded on the recording medium, said memory control means controllingthe read-out of the data from said storing means on the basis of acontrol signal from said control means.
 16. The recording apparatus asclaimed in claim 12, wherein said control means rewrites the managementdata on the recording medium on the basis of an arrangement state ofdata on the recording medium after the recording operation of saidrecording means is completed.
 17. A recording apparatus for a recordingmedium which has a data recording area on which a data recording and/orreproducing operation is carried out, and a management data area onwhich management data for managing a recording and/or reproducingoperation for the recording medium are recorded, and on which addressdata are recorded, the data being discretely recorded on the datarecording area while sectioned into plural blocks, each of which has apredetermined data amount as a data recording unit, and datarepresenting the read-out order of the plural blocks being recorded onthe management data area, said apparatus comprises:recording means forrecording data on the recording medium; storing means for temporarilystoring the input data to be recorded on the recording medium; encodermeans for encoding data read out from said storing means into recordingdata and supplying the encoded data to said recording means; and controlmeans for controlling the operation of said recording means, saidstoring means and said encoder means, wherein when new data are recordedon the recording medium in a state corresponding to where data have beenalready recorded on the recording medium and a free data recordable areaon which the new data can be recorded exists on the data recording areaof the recording medium, on the basis of the management data recorded onthe management data of the recording medium, said control means controlssaid recording means to delete, by the data amount corresponding to apredetermined data unit read out from said storing means, thealready-recorded data on the recording medium from a position on thedata recording area of the recording medium corresponding to the stateat which the recording operation of the new data is instructed to starand reads out the data from said storing means every predetermined unitand controls said recording means to record the new data from the headposition of the recordable area, and wherein if it is judged that thenew data cannot be contiguously recorded on the recording medium by saidrecording means, before the new data are recorded on the recordable areaof the recording medium, said control means further deletes thealready-recorded data on the recording medium by the same data amount asthe recording unit from the position on the data recording area of therecording medium corresponding to the state at which the recordingoperation is instructed to start.
 18. A recording apparatus for arecording medium which has a data recording area on which a datarecording and/or reproducing operation is carried out, and a managementdata area on which management data for managing a recording and/orreproducing operation for the recording medium are recorded, and onwhich address data are recorded, the data being discretely recorded onthe data recording area while sectioned into plural blocks, each ofwhich has a predetermined data amount as a data recording unit, and datarepresenting the read-out order of the plural blocks being recorded onthe management data area, said apparatus comprises:recording means forrecording data on the recording medium; storing means for temporarilystoring the input data to be recorded on the recording medium; encodermeans for encoding data read out from said storing means into recordingdata and supplying the encoded data to said recording means; and controlmeans for controlling the operation of said recording means, saidstoring means and said encoder means, wherein when new data are recordedon the recording medium in a state corresponding to where data have beenalready recorded on the recording medium and a free data recordable areaon which the new data can be recorded exists on the data recording areaof the recording medium, on the basis of the management data recorded onthe management data of the recording medium, said control means controlssaid recording means to delete, by the data amount corresponding to apredetermined data unit read out from said storing means, thealready-recorded data on the recording medium from a position on thedata recording area of the recording medium corresponding to the stateat which the recording operation of the new data is instructed to starand reads out the data from said storing means every predetermined unitand controls said recording means to record the new data from the headposition of the recordable area, and wherein if it is judged that thenew data cannot be contiguously recorded on the recording medium by saidrecording means, before the new data are recorded on the recordable areaof the recording medium, said control means deletes the already-recordeddata on the recording medium from the position on the data recordingarea of the recording medium corresponding to the state at which therecording operation is instructed to start so that the data amount ofthe data to be deleted is larger than that of the new data to berecorded on the recordable area.
 19. A recording apparatus for arecording medium which has a data recording area on which a datarecording and/or reproducing operation is carried out, and a managementdata area on which management data for managing a recording and/orreproducing operation for the recording medium are recorded, and onwhich address data are recorded, the data being discretely recorded onthe data recording area while sectioned into plural blocks, each ofwhich has a predetermined data amount as a data recording unit, and datarepresenting the read-out order of the plural blocks being recorded onthe management data area, said apparatus comprises:recording means forrecording data on the recording medium; storing means for temporarilystoring the input data to be recorded on the recording medium; encodermeans for encoding data read out from said storing means into recordingdata and supplying the encoded data to said recording means; and controlmeans for controlling the operation of said recording means, saidstoring means and said encoder means,wherein when new data are recordedon the recording medium in a state corresponding to where data have beenalready recorded on the recording medium and a free data recordable areaon which the new data can be recorded exists on the data recording areaof the recording medium, on the basis of the management data recorded onthe management data of the recording medium, said control means controlssaid recording means to delete, by the data amount corresponding to apredetermined data unit read out from said storing means, thealready-recorded data on the recording medium from a position on thedata recording area of the recording medium corresponding to the stateat which the recording operation of the new data is instructed to starand reads out the data from said storing means every predetermined unitand controls said recording means to record the new data from the headposition of the recordable area, wherein said control means deletesalready-recorded data of a recording unit on the recording medium,starting from the position on the data recording area of the recordingmedium corresponding to the state at which the recording operation isinstructed to start, reads out data from said storing means everypredetermined unit and controls said recording means to record the newdata starting from the head position of the recordable area, and whereinif it is judged that the new data cannot be contiguously recorded on therecording medium by said recording means, before the new data arerecorded on the recordable area of the recording medium, said controlmeans further deletes the already-recorded data on the recording mediumby the same data amount as the recording unit from the position on thedata recording area of the recording medium corresponding to the stateat which the recording operation is instructed to start.
 20. Therecording method as claimed in claim 5, wherein the rewriting ofmanagement data is performed on the basis of an arrangement state ofdata on the recording medium after the new data has been recorded. 21.The recording method as claimed in claim 11, wherein the rewriting ofmanagement data is performed on the basis of an arrangement state ofdata on the recording medium after the new data has been recorded. 22.The recording method as claimed in claim 21, wherein the arrangementstate of data is a reproduction time axis.